Question

In Playfair cipher what happens when two identical letters appear in the same pair?

• A. letters must be separated with a filler letter such as 'x'.
• B. one letter must be deleted.
• C. letters must be swapped.
• D. both letters must be deleted.

Hint:

In Playfair cipher, when identical letters appear in the same pair, a filler letter such as 'x' is inserted to avoid encryption errors.

Answer 1

The Correct Option is A

In Playfair cipher, if two identical letters appear in the same pair, a filler letter, typically 'x', is added to separate the repeated letters. This ensures the letters are distinct for encryption. Final Answer: \[ \boxed{A \, \text{letters must be separated with a filler letter such as 'x'}} \]